Device and method for converting gravitational force to energy

ABSTRACT

A device for converting gravitational force to energy. The device comprises a rotor. The rotor comprises an upper portion, a lower portion and a casing. A lower cavity and an upper cavity are provided in flow communication with each other. A piston is slidably received in the casing between the lower cavity and the upper cavity. When the piston slides in the casing towards the lower cavity displacement fluid exits the lower cavity and enters the upper cavity thereby causing the upper portion to be heavier than the lower portion. A pivot is provided wherein the rotor can rotate such that the upper portion becomes lower than the lower portion. A shaft is provided which is parallel to the pivot and capable of rotating with the rotor. A generator is coupled.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a device, and method, forconverting gravitational force to usable energy. More specifically, thepresent invention relates to a device, and method, for convertinggravitational energy to rotational energy whereby the rotational energycan be harnessed for beneficial purposes.

[0002] Energy generation is vital to the survival and advancement ofcivilization. There is a continual desire to harness energy fromnon-depletable resources such as wind, tidal fluctuations andgravitational force. This desire will continue until the use ofdepletable resources, such as fossil fuels, is substantially reduced.

[0003] Harnessing energy from tidal fluctuations has been explored formany years. This method is limited by proximity to an ocean and by thecorrosive nature of sea water. It is apparent to those of skill in theart that reducing mechanical losses, such as friction, is critical toefficient energy conversion. The corrosive nature of sea water iscontrary to this desire.

[0004] The use of wind energy is widely used. This method is limited bythe variability of wind. The unpredictable nature of wind requires thatany wind based energy generation system have a supplemental energysource. With high winds a wind based energy generation system must beable to respond to the wind, typically by rotation, without generatingthe maximum amount of power. This is often referred to in the art asspilling. This non-energy producing rotation causes the variouscomponents to wear unnecessarily.

[0005] Harnessing energy from gravitational pull would be of greatadvantage. Gravitational pull is relatively constant at all times and inall conditions. This would allow energy generation systems to bevirtually universal without regard for terrain, weather, or otheruncontrollable events such as those related to geography and politicalsystems. Harnessing gravitational pull would greatly benefit mankind.

[0006] Attempts to capture gravitational pull have met with limitedsuccess. Unbalanced rotating systems are described in U.S. Pat. Nos.6,363,804; 5,921,133 and 4,333,548. The large number of moving parts andengaged gears reduces the efficiency of these systems. It is a desire toreduce the number of moving parts to increase efficiency of the overallsystem. A system based on fluid flow is described in U.S. Pat. No.3,028,727. A method utilizing a threaded rod turned by a descendingweight is described in U.S. Pat. No. 6,220,394.

[0007] It has been an ongoing desire to harness gravitational forcesefficiently. This goal has been achieved with the present invention

BRIEF SUMMARY OF THE INVENTION

[0008] It is object of the present invention to provide a method ofharnessing energy from gravity.

[0009] It is another object of the present invention to harness energyefficiently and without the necessity for auxiliary power.

[0010] A particular feature of the present invention is the simplicityof the inventive device and the minimal number of moving parts requiredto achieve the stated objects.

[0011] Another particular feature is the ability to utilize the presentinvention in any location without regard for geography or environmentalconcerns.

[0012] These and other advantages, as would be realized to one ofordinary skill in the art, are provided in a device for convertinggravitational force to energy. The device comprises a rotor. The rotorcomprises an upper portion, a lower portion and a casing. A lower cavityand an upper cavity are provided in flow communication with each other.A piston is slidably received in the casing between the lower cavity andthe upper cavity. When the piston slides in the casing towards the lowercavity displacement fluid exits the lower cavity and enters the uppercavity thereby causing the upper portion to be heavier than the lowerportion. A pivot is provided wherein the rotor can rotate such that theupper portion becomes lower than the lower portion. A shaft is providedwhich is parallel to the pivot and capable of rotating with the rotor. Agenerator is coupled.

[0013] Another embodiment is provided in a device for convertinggravitational force to energy. The device comprises a rotor. The rotorcomprises a first end and a second end. A first cavity is in the firstend and a second cavity is in the second end. The second cavity is inflow communication with the first cavity. A piston, between the firstcavity and second cavity, slides in response to gravity towards thefirst end causing a displacement fluid to exit the first cavity andenter the second cavity. The shift in mass causes the rotor to beheavier on the second end. The rotor can rotate on a pivot such that thesecond end rotates to a position lower than the first end in response togravity. A shaft capable of rotating with the rotor, is coupled to agenerator.

[0014] Yet another embodiment is provided in a rotor for convertinggravitational force to rotational energy. The rotor comprises a firstend and a second end. A first cavity is in the first end and a secondcavity is in the second end. The second cavity is in flow communicationwith the first cavity. A central pivot point is between the first endand the second end. A piston is between the first end and the secondend. The piston has a fixed piston center of gravity and said rotor hasa variable rotor center of gravity. When the piston moves between thefirst end and the second end the piston center of gravity and the rotorcenter of gravity are on opposite sides of the central pivot. A shaft isparallel to the central pivot.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a cross-sectional view of an embodiment of the presentinvention prior to the response to gravity.

[0016]FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 afterthe response to gravity and prior to conversion of the response toenergy.

[0017]FIG. 3 is a schematic representation of a single rotor coupled toa generator.

[0018]FIG. 4 is a schematic representation of an embodiment of thepresent invention wherein multiple devices are coupled sequentially to agenerator.

[0019]FIG. 5 is a cross-sectional view of an embodiment of the presentinvention.

[0020]FIG. 6 is a cross-sectional view of a drive mechanism of oneembodiment of the present invention.

[0021]FIG. 7 is a cross-sectional view of a preferred rotor of thepresent invention.

[0022]FIG. 8 is a cross-sectional view of a preferred rotor of thepresent invention.

[0023]FIG. 9 is a perspective view of a preferred rotor of the presentinvention.

[0024]FIG. 10 is a schematic representation of a system of the presentinvention.

[0025]FIG. 11 is a schematic representation of a system of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The inventor of the present application have developed, throughdiligent research, a device capable of efficiently harnessing energyfrom gravitational pull. The inventors have also developed a method forincorporating such an inventive device in a system for generating energyfrom gravitational pull.

[0027] The invention will be described with reference to the figuresforming a part of the present application. In the various figuressimilar elements are numbered accordingly.

[0028] A cross-sectional view of an embodiment of the present inventionis provided, and will be described with reference to, FIGS. 1 and 2.FIG. 1 illustrates an embodiment of the present invention prior to theresponse to gravitational pull. For the sake of clarity gravitationalforce will be in the direction of the bottom of each figure.

[0029] In FIG. 1, the rotor, generally represented at 1, comprises anouter shell, 2, and an inner piston, 3. The piston is slidablydisplaceable within the outer shell. Between the outer shell and pistonare variable chambers with select pairs having correlated volumes. Apair of outer chambers, 4 and 5, are connected via a transport column,6. An outer displacement fluid, 7, freely moves between the first outerchamber, 4, and second outer chamber, 5, through the transport column,6. A pair of inner chambers, 8 and 9, are connected via a flow channelbetween the first inner chamber, 8, and second inner chamber, 9. Acounter fluid, 11, freely moves between the first inner chamber, 8, andsecond inner chamber, 9, via a flow channel, 10. The displacement fluidhas a higher density then that of the counter fluid.

[0030] In the orientation illustrated in FIG. 1, the rotor has the firstouter chamber, 4, filled with displacement fluid while the second innerchamber, 9, is filled with counter fluid. Due to gravitational pull thepiston will move downward causing displacement fluid to move from thefirst outer chamber, 4, through the transport column, 6, to the secondouter chamber, 5. When the piston has moved to its furthest extentdownward, as illustrated in FIG. 2, the second outer chamber, 5,contains displacement fluid while the second inner chamber isessentially collapsed. The first outer chamber, 4, is essentiallycollapsed and the first inner chamber, 8, contains counter fluid asshown in FIG. 2. Due to the higher density of the displacement fluidrelative to the counter fluid the rotor is heavier at the top than atthe bottom. By allowing free rotation the rotor will naturally turnaround a centrally located couple, 12. Upon reaching the fully invertedposition the configuration illustrated in FIG. 1 is re-established withthe first inner chamber and first outer chamber on the top.

[0031] The inner chambers are in flow communication with each other andthe outer chambers are in flow communication with each other. It wouldbe apparent that the inner chambers are not in flow communication withthe outer chambers. An optional, but preferred, seal, 13, is provided toseparate the inner chambers from the outer chambers. The seal may be aring around the piston as commonly employed for separating chambersabove and below a piston.

[0032] An embodiment of the present invention is further described inreference to FIG. 3. The rotor, 1, and collar, 12, as describedpreviously, are attached to a drive shaft, 14, which rotates incorrelation with the rotation of the rotor. The drive shaft, 14, is inturn coupled to a generator, 15, which generates energy in response tothe rotation of a shaft coupled thereto. Leads, 16 and 17, transport theenergy to a location of choice.

[0033] A system utilizing the present invention is provided in FIG. 4.In FIG. 4, a multiplicity of rotors, 1, are arranged inline linearly andattached to a generator, 15. The generator transports energy throughleads, 16 and 17. Each rotor, 1, is preferably in a different rotationalorientation from at least one other rotor. A secondary drive shaft, 20,transfers the rotational motion from the assembly of rotors to thegenerator. An optional, but preferred, shaft intermediate, 18, isprovided. The shaft intermediate, 18, may comprise a slip clutch wherebyrotation of the primary drive shaft, 21, is only correlated in onerotational direction with the opposite rotation being free rotation. Theprimary drive shaft, 21, may be a continuous shaft passing through theseries of rotors, 1, or a series of shafts with each shaft transferringrotational energy to the next shaft in the series towards the generator.The primary drive shaft, 21, and secondary drive shaft, 20, may be acontinuous shaft.

[0034] The number of rotors in a series is dependent on the size of eachrotor and the cycle time required for mass transfer. In one embodimentthe rotors rotate independently with each rotor imparting rotation tothe drive shaft independently through a slip clutch or similar device.Independent rotation is desired due to the increased control affordedthereby. In one embodiment the shaft intermediate, 18, comprises a shafttachometer whereby the rate of rotation of the shaft can be monitored. Acontroller in the shaft intermediate can control a rotor controller, 22,for each rotor, 1, through communication linkages, 23. Each rotorcontroller, 22, comprises a suppressor, 24, capable of suppressingrotation of the rotor preferably by engaging physically with a surfaceof the rotor. The rotor controller can delay release of each rotor toinsure complete mass transfer within the rotor and to optimise theefficiency of the system. The rotor controller and rotor suppressor arepreferably controlled electrically yet mechanical control utilizing camshafts is within the bounds of the present invention. Electrical controlis preferred, in part, due to the increased control available throughstandard digital control methods and the lower number of moving partsrequired. The rotors in a rotor assembly can all be the same size or thesize may vary for increased flexibility and control.

[0035] The rotors are preferably controlled based on system parametersand energy demand. In a preferred embodiment each rotor is coupled to adrive shaft with a slip clutch or similar device. The rotor can eitherbe configured such that the rotation is near constant thereby reducingthe necessity of a controller. It is more preferred that the controllersdelay each rotor independently to insure complete mass transfer. Eachrotor represents a non-diminishing potential energy source at full masstransfer. With multiple rotors the potential energy can be released ondemand to respond to energy demand. Based on the teachings herein one ofordinary skill in the art could determine the optimum control based onthe application.

[0036] An embodiment of the present invention is provided in FIG. 5. InFIG. 5, the rotor, 1, comprises a first outer chamber, 4, and a secondouter chamber, 5. Each outer chamber is contained within a collapsiblebladder, 30. The outer chambers are in flow communication with eachother through transport columns, 6. The inner chambers, 8 and 9, are inflow communication through the inner cavity, 31, of the shell, 2.Optional vents, 33, in the shell, 2, allow fluid to readily exchangewith the environment. Vents are particularly suitable when the counterfluid is air. The shaft, 21, and slip clutch mechanism will be morefully described with reference to FIG. 6.

[0037] A suitable slip clutch is illustrated in FIG. 6. The drive shaft,21, comprises at least one ratchet cam, 34. A pin, 35, reversiblyreceived in a recess, 37, engages the drive face, 36, of the ratchet camto rotate the shaft. If the shaft is rotating faster than the rotor orif the rotor is idle the cam face, 36, persuades the pin into therecess, 37, as it rotates and the drive shaft and rotor are decoupled. Aspring, 38, persuades the pin to protrude to a drive face engagingposition. The term “slip clutch”, as used herein, is used in accordancewith the description common in the art. Particularly preferred is areversibly engageable couple and more preferably the couple isunidirectional wherein rotation in one direction couples the twocomponents while reversing one of the components decouples the rotation.

[0038] An embodiment of a rotor of the present invention is illustratedin cross-sectional, partial cut-away view in FIG. 7. In FIG. 7, therotor, generally represented at 1, comprises an outer casing, 40. Theshape of the outer casing is not particularly limiting. Cylindrical is apreferred shape due to the simplicity of manufacture. Secured to theinterior of the outer casing are two working chambers, 41 and 42, and anoptional centrally located guide chamber, 43. The working chambers arepreferably of substantially identical volume. The piston, 44, comprisesa pair of compression plates, 45 and 46, which force displacement fluidfrom one working chamber to the other in accordance with the operationof the rotor as set forth herein. A centrally located weight, 47, slidesin the guide chamber, 43, in response to gravitational force asdescribed previously. A transfer tube, 48, connects the working chambersand allows displacement fluid to traverse from one working chamber tothe other in response to the lower chamber being compressed by thecompression plate due to the force of gravity on the piston. The twocompression plates and weight are connected one to the other preferablyby the transfer tube. The guide chamber and that portion of each workingchambers which is interior to the compression plate are preferablyconnected by tubes, 49. The tubes allow free flow of counter fluidbetween the inner portions of the working chamber and the guide chamberto avoid restricting travel of the piston due to counter fluidcompression, turbulence, boundary flow restrictions or any conditionwhich would cause the flow of the counter fluid to limit mass transfer.A drive shaft, 50, preferably attached to the outer casing, 40, couplesto a generator as described previously. An idler axle, 51, parallel tothe drive shaft provides a support for the rotor.

[0039] Another embodiment of the rotor is illustrated in cross-sectionalview in FIG. 8. In FIG. 8, the rotor comprises an outer casing, 40.Interior to the outer casing is a piston comprising a pair ofcompression plates, 45 and 46, equidistant from an optional weight, 47.The compression plates and weight are preferably attached by a transfertube, 48. Additional stabilizing rods, 52, may be employed for stabilityif necessary. The central weight, 47, comprises bleed devices, 53, suchas exterior grooves or holes through the weight to avoid any resistancewhich could be caused by counter fluid. Bladders, 54 and 55, betweeneach compression plate and the end cap, 56, form a continuous chamberwith the transfer tube, 48, allowing displacement fluid to transfertherebetween. It would be apparent from the descriptions elsewhereherein that as one bladder is compressed the other bladder expandsproportionally. The shape of the weight is not limiting. Shapes whichminimize contact with the interior of the outer casing are preferred todecrease friction. A drive shaft, 50, and idler shaft, 51, allow therotor to be rotatably suspended in bearings or similar friction reducingmeans as known in the art.

[0040] A preferred rotor is illustrated in FIG. 9. In FIG. 9, the rotor,1, is elongated parallel to the drive shaft, 14. A rotor which iselongated parallel to the drive shaft is preferable since the amount ofrotation required to have the center of balance sufficiently offset toinitiate rotation is minimized. The longer, and narrower, the rotor thebetter up to the limit of restricting mass movement of the piston andfluids in a timely manner.

[0041] The rotor of the present invention can be used singularly,wherein a single rotor turns a generator, or in multiples whereinmultiple rotors turn a generator. An embodiment of a the presentinvention comprising multiple rotors is illustrated schematically inFIG. 10. In FIG. 10, a multiplicity of rotor assemblies, 63, each with adrive shaft, 65, attached thereto, is coupled to a coupler, 60. Thecoupler, 60, receives rotational energy from the rotor assemblies, andtransfers the combined rotational energy to a single secondarydriveshaft, 61, which is in turn coupled to a generator, 15. Anotherembodiment is provided in FIG. 11 wherein the generator receivesrotational energy from multiple rotors. It is well within the skill ofone of ordinary skill in the art to configure a coupler to multiplerotating shafts for a common shaft output. A rotor assembly may compriseone or more rotors.

[0042] The function of the piston is to displace fluid from a lowerchamber to the upper chamber. The weight of the piston must therefore bemore than the weight of the volume of compression fluid. An excessiveweight is neither necessary nor desired since the higher the weight ofthe piston the more friction will be created in the rotation mounting.By necessity the weight of the piston is shifted towards the lowerportion of the rotor as rotation initiates therefore the piston is acounterbalance to the displacement fluid. For this reason, it is mostdesirable that the mass of the piston be centrally located such that themass shift is as close as possible to the rotation axis. The aspectratio, or height over cross-sectional area, of the rotor, and piston, isnot limiting and is selected based on the system demands includingspace, power required, number of rotors, etc.

[0043] The displacement fluid and counter fluid are not limiting exceptthat the total weight of displacement fluid displaced is higher than theweight of counter fluid displaced. Both the displacement fluid and thecounter fluid are preferable selected from materials which flow well.Heavier displacement fluids are preferred. The fluid may include variousingredients known in the art including stabilizers, surfactants, etc.Particularly suitable displacement fluids include water, mercury, andlow viscosity high density organic solvents. Water is the most preferreddisplacement fluid due to, among other things, cost and availability.Particularly suitable counter fluids are gases, particularly air.

[0044] The generator is any device suitable for converting rotationalenergy to a usable energy form. Particularly preferred generatorsproduce electricity or pressure. Electrical generators are well knownand further elaboration herein is not necessary. Pressure generators areknown to include fluid pumps such as water pumps, hydraulic pumps, airpumps and the like wherein the moving fluid is further used toaccomplish a task. An electrical generator is most preferred.

[0045] Bladders are not limited by their material of construction withthe exception of the flexibility which must be sufficient for thebladder to expand and extract without hindering the mass transfer. Themanner in which the bladder is attached is also not critical to thepresent invention.

[0046] Flow communication, in the context of the present invention, isspecific to a mechanism for transferring fluid from one vicinity to theother. In general, the area containing fluid has a fixed volume withincomplimentary regions wherein one contracts concurrently with oneexpanding and the flow communication is a preferably fixed volume regionthere between.

[0047] The invention has been described with particular emphasis on thepreferred embodiments. It would be realized from the teachings hereinthat other embodiments, alterations, and configurations could beemployed without departing from the scope of the invention which is morespecifically set forth in the claims which are appended hereto.

Claimed is:
 1. A device for converting gravitational force to energycomprising: a rotor comprising an upper portion and a lower portion andfurther comprising: a casing; a lower cavity and an upper cavity in flowcommunication with said lower cavity; a piston slidably received in saidcasing and between said lower cavity and said upper cavity wherein whensaid piston slides in said casing towards said lower cavity displacementfluid exits said lower cavity and enters said upper cavity therebycausing said upper portion to be heavier than said lower portion; apivot wherein said rotor can rotate on said pivot such that said upperportion becomes lower than said lower portion; and a shaft parallel tosaid pivot and capable of rotating with said rotor; and a generatorcoupled to said shaft.
 2. The device of claim 1 comprising at least tworotors.
 3. The device of claim 2 wherein said at least two rotors arecoupled linearly.
 4. The device of claim 2 wherein said at least rotorsare coupled to a coupler.
 5. The device of claim 1 wherein saidgenerator is an electrical generator.
 6. The device of claim 1 whereinsaid lower cavity comprises a first bladder and said upper cavitycomprises a second bladder and said displacement fluid moves betweensaid first bladder and said second bladder as said piston slides.
 7. Thedevice of claim 1 wherein said piston comprises compression plates. 8.The device of claim 7 further comprising a counter fluid between saidcompression plates.
 9. The device of claim 8 further comprising a firstinner chamber and a second inner chamber in flow communication with saidfirst inner chamber wherein said counter fluid flows between said firstinner chamber and said second inner chamber in response to said pistonsliding.
 10. The device of claim 9 wherein said first inner chambercomprises a first bladder and said second inner chamber comprises asecond bladder.
 11. The device of claim 7 wherein said piston comprisesa weight.
 12. The device of claim 11 wherein said weight is between saidcompression plates.
 13. The device of claim 1 wherein said pistoncomprises a transfer tube between said upper cavity and said lowercavity.
 14. The device of claim 1 wherein said rotor is coupled to saidgenerator by a slip clutch.
 15. The device of claim 1 wherein said rotoris elongated parallel to said shaft.
 16. The device of claim 1 furthercomprising a coupler between said shaft and said generator.
 17. Thedevice of claim 1 further comprising a rotor controller and a suppressorcapable of suppressing rotation of said rotor.
 18. The device of claim 1wherein said shaft is coupled to said rotor by a slip clutch.
 19. Thedevice of claim 18 wherein said slip clutch is a unidirectional slipclutch.
 20. A device for converting gravitational force to energycomprising: a rotor comprising an first end and a second end and furthercomprising: a first cavity in said first end; a second cavity in saidsecond end wherein said second cavity is in flow communication with saidfirst cavity; a piston between said first cavity and said second cavitywherein when said piston slides in response to gravity towards saidfirst end a displacement fluid exits said first cavity and enters saidsecond cavity thereby causing said rotor to be heavier on said secondend; a pivot wherein said rotor can rotate on said pivot such that saidsecond end rotates to a position lower than said first end in responseto gravity; a shaft capable of rotating with said rotor; and a generatorcoupled to said shaft.
 21. The device of claim 20 comprising at leasttwo rotors.
 22. The device of claim 21 wherein at least two rotors arecoupled linearly.
 23. The device of claim 21 wherein said at leastrotors are coupled to a coupler.
 24. The device of claim 20 wherein saidgenerator is an electrical generator.
 25. The device of claim 20 whereinsaid first cavity comprises a first bladder and said second cavitycomprises a second bladder and said displacement fluid moves betweensaid first bladder and said second bladder as said piston slides. 26.The device of claim 20 wherein said piston comprises compression plates.27. The device of claim 26 further comprising a counter fluid betweensaid compression plates.
 28. The device of claim 27 further comprising afirst inner chamber and a second inner chamber in flow communicationwith said first inner chamber wherein said counter fluid flows betweensaid first inner chamber and said second inner chamber in response tosaid piston sliding.
 29. The device of claim 28 wherein said first innerchamber comprises a first bladder and said second inner chambercomprises a second bladder.
 30. The device of claim 28 wherein saidpiston comprises a weight.
 31. The device of claim 30 wherein saidweight is between said compression plates.
 32. The device of claim 20wherein said piston comprises a transfer tube between said upper cavityand said lower cavity.
 33. The device of claim 20 wherein said rotor iscoupled to said generator by a slip clutch.
 34. The device of claim 20wherein said rotor is elongated parallel to said shaft.
 35. The deviceof claim 20 further comprising a coupler between said shaft and saidgenerator.
 36. The device of claim 20 further comprising a rotorcontroller and a suppressor capable of suppressing rotation of saidrotor.
 37. The device of claim 20 wherein said shaft is coupled to saidrotor by a slip clutch.
 38. The device of claim 37 wherein said slipclutch is a unidirectional slip clutch.
 39. A rotor for convertinggravitational force to rotational energy comprising: a first end and asecond end: a first cavity in said first end; a second cavity in saidsecond end wherein said second cavity is in flow communication with saidfirst cavity; a central pivot point between said first end and saidsecond end; a piston between said first end and said second end whereinsaid piston has a fixed piston center of gravity and said rotor has avariable rotor center of gravity wherein as said piston moves betweensaid first end and said second end said piston center of gravity andsaid a rotor center of gravity are on opposite sides of said centralpivot; and a shaft parallel to said central pivot.
 40. The rotor ofclaim 39 wherein said first cavity comprises a first bladder and saidsecond cavity comprises a second bladder and said displacement fluidmoves between said first bladder and said second bladder as said pistonslides.
 41. The rotor of claim 39 wherein said piston comprisescompression plates.
 42. The rotor of claim 41 further comprising acounter fluid between said compression plates.
 43. The rotor of claim 42further comprising a first inner chamber and a second inner chamber inflow communication with said first inner chamber wherein said counterfluid flows between said first inner chamber and said second innerchamber in response to said piston sliding.
 44. The rotor of claim 43wherein said first inner chamber comprises a first bladder and saidsecond inner chamber comprises a second bladder.
 45. The rotor of claim41 wherein said piston comprises a weight.
 46. The rotor of claim 45wherein said weight is between said compression plates.
 47. The rotor ofclaim 39 wherein said piston comprises a transfer tube between saidfirst cavity and said second cavity.
 48. The rotor of claim 39 whereinsaid rotor is elongated parallel to said shaft.